Last week I heard the GoodSchist podcast featuring Chris of good schist, Chris of Highly Allochthonous and Julia of The Ethical Paleontologist. That talk featured volcanism among other topics.
Now, OnPoint Radio has a one hour talk on volcanism. Invited guest are Peter Cervelli and Cyrus Read from the Alaska Volcano Observatory, Marianne Guffanti of the U.S Geological Survey and Mark Simons of Seismological Laboratory at Cal Tech. They talk with Tom Ashbrook and callers from all over the U.S. about the recent volcanic activity in Alaska, Chile and Tonga.
Is Bobby Jindal listening?
And here's a video from AP of the Tonga eruption
Monday, March 30, 2009
Univ. Of Florida Geology Dept. Faces Deep Cuts
I'm from Seminole country, rivals of the Florida Gators but this goes beyond football rivalry. Depressing news coming out of the Univ. of Florida. Their geology department is facing deep cuts. The plan is to fire all staff except ten tenure faculty.
That is just a devastation loss to an excellent graduate research and teaching program. From the perspective of my field, Univ. of Florida carbonate geology research group has done some pretty impressive work on Cenozoic carbonate geology of Florida. Pharyngula has an inimitable post on how cuts to graduate departments affect teaching, research and the quality of education. Joseph Meert who is faculty at Univ. of Florida geology department adds his thoughts.
And the Florida Citizen For Science site details just how wrong this decision is given the central role geology departments play in Florida society and economy.
In an era of ‘green technology’, environmental awareness, the need for natural resource management, global climate change and the need to preserve access to freshwater, the thought of decimating a Geology Department borders on insanity. This is especially true of a flagship university that sits about 150 feet above sea level in a state where the top three revenue generators are, in order, tourism, agriculture and mining.
When faced with required budget cuts at a land grant university, is the best solution really to cut one department best poised to address problems directly related to the states three biggest income sources?
I found out recently though that these cuts are not just affecting Universities. The state Dept. of Environmental Protection is also facing severe budget cuts. A friend who is a senior administrator with the Florida Geological Survey tells me that she has had to prepare "survival reports" essentially justifying the existence of the various program areas within the survey.
This one brings it closer to home. I have worked with the Florida Geology Survey for several years and I know friends who could be affected by these looming cuts. One area that has been facing cuts even before the current crises is the coastal geology program.
???? ....Ain't that just a daft idea?
Close to Tallahassee where the survey is located, the Gulf of Mexico coastline with its barrier islands, beaches, coastal wetlands and estuaries is a major player in the state tourism industry. This geological complex is coming under increasing threat from coastal development, hurricanes and in the medium and long term possibly from sea-level rise.
The State of Florida should be strengthening its coastal geology program not thinking of cutting it. It just defies common sense that a knowledge base so crucial to the health and economy of Florida coastal communities is being frozen.
Read this acknowledgment dated October 2008 about the importance of earth sciences and the role it plays in Florida society from the Governor of Florida Charlie Crist. Shouldn't such a strong public acceptance of the importance of geology from the highest political office in the state be followed by a commitment to ensure continuity of funding for university and state geology programs? I see it as a massive violation of public trust for the governor to have signed this document and then to go ahead and butcher geology funding left right and center on the premise that cuts in geology will do the least damage to the University as a whole. That premise is short sighted and faulty but unfortunately it may be a decade or so before the repercussions of this decision are fully realized by Florida society.
Tip: Nanopolitan
That is just a devastation loss to an excellent graduate research and teaching program. From the perspective of my field, Univ. of Florida carbonate geology research group has done some pretty impressive work on Cenozoic carbonate geology of Florida. Pharyngula has an inimitable post on how cuts to graduate departments affect teaching, research and the quality of education. Joseph Meert who is faculty at Univ. of Florida geology department adds his thoughts.
And the Florida Citizen For Science site details just how wrong this decision is given the central role geology departments play in Florida society and economy.
In an era of ‘green technology’, environmental awareness, the need for natural resource management, global climate change and the need to preserve access to freshwater, the thought of decimating a Geology Department borders on insanity. This is especially true of a flagship university that sits about 150 feet above sea level in a state where the top three revenue generators are, in order, tourism, agriculture and mining.
When faced with required budget cuts at a land grant university, is the best solution really to cut one department best poised to address problems directly related to the states three biggest income sources?
I found out recently though that these cuts are not just affecting Universities. The state Dept. of Environmental Protection is also facing severe budget cuts. A friend who is a senior administrator with the Florida Geological Survey tells me that she has had to prepare "survival reports" essentially justifying the existence of the various program areas within the survey.
This one brings it closer to home. I have worked with the Florida Geology Survey for several years and I know friends who could be affected by these looming cuts. One area that has been facing cuts even before the current crises is the coastal geology program.
???? ....Ain't that just a daft idea?
Close to Tallahassee where the survey is located, the Gulf of Mexico coastline with its barrier islands, beaches, coastal wetlands and estuaries is a major player in the state tourism industry. This geological complex is coming under increasing threat from coastal development, hurricanes and in the medium and long term possibly from sea-level rise.
The State of Florida should be strengthening its coastal geology program not thinking of cutting it. It just defies common sense that a knowledge base so crucial to the health and economy of Florida coastal communities is being frozen.
Read this acknowledgment dated October 2008 about the importance of earth sciences and the role it plays in Florida society from the Governor of Florida Charlie Crist. Shouldn't such a strong public acceptance of the importance of geology from the highest political office in the state be followed by a commitment to ensure continuity of funding for university and state geology programs? I see it as a massive violation of public trust for the governor to have signed this document and then to go ahead and butcher geology funding left right and center on the premise that cuts in geology will do the least damage to the University as a whole. That premise is short sighted and faulty but unfortunately it may be a decade or so before the repercussions of this decision are fully realized by Florida society.
Tip: Nanopolitan
Thursday, March 26, 2009
The Power Of An Image- Western Ghat Escarpment
Sometimes an image has the power to stop you in your tracks. I look at images all the time, mostly satellite images, sometimes old aerial photos. A few minutes ago I was mucking around looking for elevation data on India, and tucked in a folder I hadn't browsed for a while was a USGS GTOPO30 DEM. This is a DEM with a horizontal grid spacing of 30 arc second which is about 1 km.
I imported the surface in Manifold GIS. A quick thematic display using the standard Altitude palette, but the result was breathtaking. Below is the western ghat escarpment stretching from north of Mumbai to south of Goa. That's more than 400 km. Its made up of the Deccan basalts along most of the extent of this image but just north of Goa the basalts pinch out and the Precambrian shield region begins.
It goes on for some distance to the south right up to the state of Kerala, but I had to juggle the extent so as to find the right balance between showing it's impressive span but still to be close enough for the sharp topographic divide between the coastal plains and the plateau to come through.
It does so in a marvelous fashion. The darker green coastal plains crash against, almost seem to subduct underneath the long wriggly escarpment, its shadow highlighting the near vertical relief. The local relief is spectacular, more than 1000-1500 feet cliffs and gorges. The escarpment is the edge of an uplifted and east tilted plateau. As a result all the major rivers of peninsular India in this region have easterly drainage. The drainage is antecedent. Post Deccan volcanic but before western ghat uplift. As a result there are meandering gorges and drainage cutting across gentle fold axis.
I was in a hurry to post this. I didn't project the surface, left it in geographic co-ordinates. The scale says 1 deg which is about 110 km at equator.
I travel across the escarpment often. In a car it takes about 20 minutes to an hour to cross depending upon where along its length you are making the crossing. The climatic contrast between the warm humid coastal plains and the dry cooler plateau is noticeable and in summers desirable. You can trek across it too along some pretty demanding trails or try to mountaineer the sheer cliffs.
Now that would be an experience!
It's one of the great geological features I have witnessed and I live about an hour's drive from it.
I imported the surface in Manifold GIS. A quick thematic display using the standard Altitude palette, but the result was breathtaking. Below is the western ghat escarpment stretching from north of Mumbai to south of Goa. That's more than 400 km. Its made up of the Deccan basalts along most of the extent of this image but just north of Goa the basalts pinch out and the Precambrian shield region begins.
It goes on for some distance to the south right up to the state of Kerala, but I had to juggle the extent so as to find the right balance between showing it's impressive span but still to be close enough for the sharp topographic divide between the coastal plains and the plateau to come through.
It does so in a marvelous fashion. The darker green coastal plains crash against, almost seem to subduct underneath the long wriggly escarpment, its shadow highlighting the near vertical relief. The local relief is spectacular, more than 1000-1500 feet cliffs and gorges. The escarpment is the edge of an uplifted and east tilted plateau. As a result all the major rivers of peninsular India in this region have easterly drainage. The drainage is antecedent. Post Deccan volcanic but before western ghat uplift. As a result there are meandering gorges and drainage cutting across gentle fold axis.
I was in a hurry to post this. I didn't project the surface, left it in geographic co-ordinates. The scale says 1 deg which is about 110 km at equator.
I travel across the escarpment often. In a car it takes about 20 minutes to an hour to cross depending upon where along its length you are making the crossing. The climatic contrast between the warm humid coastal plains and the dry cooler plateau is noticeable and in summers desirable. You can trek across it too along some pretty demanding trails or try to mountaineer the sheer cliffs.
Now that would be an experience!
It's one of the great geological features I have witnessed and I live about an hour's drive from it.
Wednesday, March 25, 2009
Mapping India Using GeoCommons
Take a look at this great web mapping application. I could plot spatial data about India in a matter of minutes and make a presentable map and then share the results with like minded citizens.
FortiusOne a geographic visualization and location intelligence company has created GeoCommons - a repository for public domain data. It is a free service. You can register as a user and browse through extensive public domain datasets. This you do through a Finder module. You can then select the dataset you are interested in and either
1) download it as a Shapefile or KML (keyhole markup language) format
2) Read details of the data
3) Plot that data on a map with Maker using a background of your choice (satellite, terrain, streetview, solid). You can thematically plot your results using different attributes from the same dataset just like you can in a GIS. But this one is for free.
You can share the results of your mapping by saving them in your account and distributing the link and by downloading the results as a KML file which you can then overlay on Google Earth or Google Maps or Virtual Earth.
Here's the result of a quick experiment that I did with some India data. I picked up the CARMA (Carbon Monitoring for Action) carbon emissions from power plants dataset and made two maps in Maker. The one below shows energy generation by power plant. The size of the dots is proportional to the amount of energy generated by individual power plants. As I mentioned you can download this dataset and get you hands on data you can use and manipulate in more sophisticated spatial analysis software, but most people don't have access to this.
The distribution of mega power plants mostly follow the coal belt. You can see the largest dots are all in the central and eastern part of the country where most of India's coal deposits are situated.
The second map uses the same dataset but plots another attribute, energy intensity. This is the amount of CO2 emitted per unit of electricity generated. It is a measure of energy efficiency.
Notice that the energy intensity values in the upper range exceed average values for coal plants in the U.S, which are about 1800-2200 lbs CO2/MWh. The CARMA data I downloaded didn't categorize plants according to fuel burnt. Gas is a cleaner fuel than coal and it's a fair guess that these largest plants are coal fired. Natural gas accounts for just about 10% of power generated in India while coal accounts for about 58%. Indian coal power plants are much more inefficient at generating power than the U.S. The National Action Plan on Climate Change has an Energy Efficiency Mission, i.e. a specific directive to improve energy efficiency. It has its work cut out in the coming years.
Now hold on before you get too excited. The datasets for the U.S are vast but for India you get a very limited stock to work with. Contributions to GeoCommons is voluntary and till date I am guessing very few organizations in India using and creating public domain data know about this site. Most of the data currently available is Census data. Why such a bias? Well, this data is freely available from the Census website (site is under construction). It is stored in a non-spatial tabular format. This data has been pulled out from this site by a user and converted into a geographic format. That's easy to do with the tabular census available with the government.
That's because the data is aggregated by administrative units. If you have already have a base map with state and other administrative boundaries (which is freely available), its easy to just attach this tabular data to the geometric data using the administrative unit name as a key. This is not possible with say natural resources data where boundaries cut across administrative units. This type of data has the geometry stored along with other attributes in a special geographic format. And getting this data from the government is a lengthy process.
So how long before we start seeing more diverse datasets on India in social mapping sites like GeoCommons. That does depend upon how quickly the government implements the National Spatial Data Infrastructure, an initiative to provide easy access to public domain spatial data. Off course the availability of this data has to be coupled with government permission to upload these data onto a third party database. Right now I am not sure if having acquired government data whether you can share it using the kind of distributive model that GeoCommons uses. The rules on this are fuzzy and I really hope the NSDI will bring in some clarification of the governments stance on value addition and data sharing and see an end to the excessively restrictive and regulatory mindset that has limited the innovative use of spatial data in this country.
You don't have to wait until the NSDI takes shape to start contributing your own data to GeoCommons. If you are an organization working with spatial datasets and want to share this data, you can right now upload your data to GeoCommons. When you do so you are agreeing to its free use by others under the Creative Commons license. Anyone will be able to use this data as long as they acknowledge the data creators which is you and the data managers which is GeoCommons.
Social mapping, citizen cartography and a data sharing mechanism to initiate civic discussions on problems that have a spatial angle to them all without an expensive GIS overhead.
Try it out.
FortiusOne a geographic visualization and location intelligence company has created GeoCommons - a repository for public domain data. It is a free service. You can register as a user and browse through extensive public domain datasets. This you do through a Finder module. You can then select the dataset you are interested in and either
1) download it as a Shapefile or KML (keyhole markup language) format
2) Read details of the data
3) Plot that data on a map with Maker using a background of your choice (satellite, terrain, streetview, solid). You can thematically plot your results using different attributes from the same dataset just like you can in a GIS. But this one is for free.
You can share the results of your mapping by saving them in your account and distributing the link and by downloading the results as a KML file which you can then overlay on Google Earth or Google Maps or Virtual Earth.
Here's the result of a quick experiment that I did with some India data. I picked up the CARMA (Carbon Monitoring for Action) carbon emissions from power plants dataset and made two maps in Maker. The one below shows energy generation by power plant. The size of the dots is proportional to the amount of energy generated by individual power plants. As I mentioned you can download this dataset and get you hands on data you can use and manipulate in more sophisticated spatial analysis software, but most people don't have access to this.
The distribution of mega power plants mostly follow the coal belt. You can see the largest dots are all in the central and eastern part of the country where most of India's coal deposits are situated.
The second map uses the same dataset but plots another attribute, energy intensity. This is the amount of CO2 emitted per unit of electricity generated. It is a measure of energy efficiency.
Notice that the energy intensity values in the upper range exceed average values for coal plants in the U.S, which are about 1800-2200 lbs CO2/MWh. The CARMA data I downloaded didn't categorize plants according to fuel burnt. Gas is a cleaner fuel than coal and it's a fair guess that these largest plants are coal fired. Natural gas accounts for just about 10% of power generated in India while coal accounts for about 58%. Indian coal power plants are much more inefficient at generating power than the U.S. The National Action Plan on Climate Change has an Energy Efficiency Mission, i.e. a specific directive to improve energy efficiency. It has its work cut out in the coming years.
Now hold on before you get too excited. The datasets for the U.S are vast but for India you get a very limited stock to work with. Contributions to GeoCommons is voluntary and till date I am guessing very few organizations in India using and creating public domain data know about this site. Most of the data currently available is Census data. Why such a bias? Well, this data is freely available from the Census website (site is under construction). It is stored in a non-spatial tabular format. This data has been pulled out from this site by a user and converted into a geographic format. That's easy to do with the tabular census available with the government.
That's because the data is aggregated by administrative units. If you have already have a base map with state and other administrative boundaries (which is freely available), its easy to just attach this tabular data to the geometric data using the administrative unit name as a key. This is not possible with say natural resources data where boundaries cut across administrative units. This type of data has the geometry stored along with other attributes in a special geographic format. And getting this data from the government is a lengthy process.
So how long before we start seeing more diverse datasets on India in social mapping sites like GeoCommons. That does depend upon how quickly the government implements the National Spatial Data Infrastructure, an initiative to provide easy access to public domain spatial data. Off course the availability of this data has to be coupled with government permission to upload these data onto a third party database. Right now I am not sure if having acquired government data whether you can share it using the kind of distributive model that GeoCommons uses. The rules on this are fuzzy and I really hope the NSDI will bring in some clarification of the governments stance on value addition and data sharing and see an end to the excessively restrictive and regulatory mindset that has limited the innovative use of spatial data in this country.
You don't have to wait until the NSDI takes shape to start contributing your own data to GeoCommons. If you are an organization working with spatial datasets and want to share this data, you can right now upload your data to GeoCommons. When you do so you are agreeing to its free use by others under the Creative Commons license. Anyone will be able to use this data as long as they acknowledge the data creators which is you and the data managers which is GeoCommons.
Social mapping, citizen cartography and a data sharing mechanism to initiate civic discussions on problems that have a spatial angle to them all without an expensive GIS overhead.
Try it out.
Saturday, March 21, 2009
Land Plants And Expression Of Disconformities in Limestone Sequences
Geological Processes and Evolution - 2
A paper in the January issue of Geology looks at the influence of land plants on the detrital sedimentary cycle.
Evidence from Middle Ordovician paleosols for the predominance of alkaline groundwater at the dawn of land plant radiation -
Atmospheric CO2 has decreased by about 500 times from Archean times to recent. So rain water composition has become less acidic over time. But groundwater does not show such a temporal decrease in acidity. In fact groundwater may be more acidic on average in younger geological periods compared with the Archean. This is because of the evolution of land plants by Silurian times which started contributing organic acids to groundwater. The amount of organic acid from the plant system easily offset any decrease in rain water carbonic acid from decreasing atmospheric CO2.
The authors identify a geologic time window - Mid-Late Proterozoic to Late Ordovician when groundwaters were more alkaline than the time period before and after. This is because a) a spurt of continental crust formation by mid-late Proterozoic started consuming CO2 in weathering reactions and b) this stable continental crust provided a substrate for accumulation of carbonate sediments, another important CO2 sink. By early Paleozoic, atmospheric CO2 had dropped compared to the Archean (it was still about 10 times more than the recent ~ 300 ppm). And land plants had not yet evolved.
The paper in Geology demonstrates using the geochemistry of mid-Ordovician paleosols that the groundwater was alkaline in composition. There is some interesting geochemistry for those into such things like element mobility. Other studies in the past have focussed on the detrital composition of sediments and have come to the same conclusions. For example there is an abundance of detrital illite and K feldspar in the mud and sand fractions of early Paleozoic sediments as compared with younger sediments from similar provenance. In acidic groundwater K is mobile and is taken up by chelation into land plants or is transported away in solution. So diagenetic illite is more common in post-Paleozoic sediments.
I have often run into the influence of land plants on sediments from a different perspective, one that involves identification of exposure surfaces in carbonate sequences. Post Silurian during sea-level drops the exposed sea bed will get colonized by land plants. The release of organic acids leads to acidic groundwater and rapid dissolution of the carbonate sediment. Add to that is the physical disruption of sediment by the action of roots and burrowing fauna. All this leads to the development of a highly irregular, pitted surfaces with collapse structures, caverns and infill breccias and a deep chalky weathering profile often with Fe hydroxide stains and crusts. The image below is of a Pleistocene skeletal limestone from a mid shelf facies setting exposed in south Florida for the past several tens of thousands of years.
Notice the karst like profile already developing and penetrating the sequence. If this surface is overlain by sediments in the future the disconformity would be easy to spot in the field.
No such luck in the mid-late Ordovician. Look at this mid-late Ordovician disconformity in the image below. This is the top of a depositional cycle, a parasequence boundary in stratigraphic jargon. The facies setting is similar to the Pleistocene example above.
The climate too has been interpreted to be warm and seasonally moist. The contact just above the coin is an exposure surface. It is a planar surface with a few small pits but overall there is no evidence of the kind of disruptive features you see underneath younger disconformities.
This cycle is part of a cyclic sequence. I could never get a handle on the individual cycle frequency but using regional stratigraphic markers and conodont biostratigraphy a rough estimate is that surface was exposed for tens of thousands of years during Richmondian sea level falls. There is plenty of microscopic evidence of exposure in the form of preserved vadose diagenetic fabrics, but in the field it looks just like a bedding plane. In the late Ordovician there was a land plant cover but it was mostly of the bryophyte grade i.e. mosses and liverworts. These plants don't have disruptive root systems and don't release the massive quantities of organic acids for penetrative weathering profiles to develop.
There are other controls in carbonate systems that can form karstic surfaces in the absence of land plants. One is the facies setting. Supratidal and sabkha facies with dolomite and evaporite minerals dissolve quickly in carbonate under saturated groundwater and these facies often develop the kind of disruptive weathering profiles you associated with a land plant cover.
And the other control is time. Very long lived exposure of limestone, surfaces that are exposed to meteoric condition for tens of millions of years will eventually succumb and form distinctive karst. The image below is of the Knox unconformity between lower Ordovician passive margin platform carbonates and a mid Ordovician foreland basin sequence.
The Knox surface developed during a major sea-level fall that lasted at least 10 million years. A mature karst terrain developed across facies tracts. Sinkhole and caverns fills and intraformational breccias can be seen to depths of 250 m beneath the unconformity.
There have been a couple of recent studies that make connections between evolution and geological processes. One dealt with an increase in diversity in mineral species after the evolution of photosynthesis. The other pointed out a connection between sea water chemistry, evolution of animals and skeletal mineralogy.
Geology may influence evolution. The paper points out that the early radiation of land plants likely took place in alkaline groundwaters. That may explain the affinity for alkali shown by many land plant groups. Subsequently as plant life took hold over terra firma, evolution influenced geology through the transition to acidic groundwater, detrital and diagenetic sediment composition, element mobility and soil composition and characteristics of disconformities.
See: Geological Processes and Evolution
A paper in the January issue of Geology looks at the influence of land plants on the detrital sedimentary cycle.
Evidence from Middle Ordovician paleosols for the predominance of alkaline groundwater at the dawn of land plant radiation -
Atmospheric CO2 has decreased by about 500 times from Archean times to recent. So rain water composition has become less acidic over time. But groundwater does not show such a temporal decrease in acidity. In fact groundwater may be more acidic on average in younger geological periods compared with the Archean. This is because of the evolution of land plants by Silurian times which started contributing organic acids to groundwater. The amount of organic acid from the plant system easily offset any decrease in rain water carbonic acid from decreasing atmospheric CO2.
The authors identify a geologic time window - Mid-Late Proterozoic to Late Ordovician when groundwaters were more alkaline than the time period before and after. This is because a) a spurt of continental crust formation by mid-late Proterozoic started consuming CO2 in weathering reactions and b) this stable continental crust provided a substrate for accumulation of carbonate sediments, another important CO2 sink. By early Paleozoic, atmospheric CO2 had dropped compared to the Archean (it was still about 10 times more than the recent ~ 300 ppm). And land plants had not yet evolved.
The paper in Geology demonstrates using the geochemistry of mid-Ordovician paleosols that the groundwater was alkaline in composition. There is some interesting geochemistry for those into such things like element mobility. Other studies in the past have focussed on the detrital composition of sediments and have come to the same conclusions. For example there is an abundance of detrital illite and K feldspar in the mud and sand fractions of early Paleozoic sediments as compared with younger sediments from similar provenance. In acidic groundwater K is mobile and is taken up by chelation into land plants or is transported away in solution. So diagenetic illite is more common in post-Paleozoic sediments.
I have often run into the influence of land plants on sediments from a different perspective, one that involves identification of exposure surfaces in carbonate sequences. Post Silurian during sea-level drops the exposed sea bed will get colonized by land plants. The release of organic acids leads to acidic groundwater and rapid dissolution of the carbonate sediment. Add to that is the physical disruption of sediment by the action of roots and burrowing fauna. All this leads to the development of a highly irregular, pitted surfaces with collapse structures, caverns and infill breccias and a deep chalky weathering profile often with Fe hydroxide stains and crusts. The image below is of a Pleistocene skeletal limestone from a mid shelf facies setting exposed in south Florida for the past several tens of thousands of years.
Notice the karst like profile already developing and penetrating the sequence. If this surface is overlain by sediments in the future the disconformity would be easy to spot in the field.
No such luck in the mid-late Ordovician. Look at this mid-late Ordovician disconformity in the image below. This is the top of a depositional cycle, a parasequence boundary in stratigraphic jargon. The facies setting is similar to the Pleistocene example above.
The climate too has been interpreted to be warm and seasonally moist. The contact just above the coin is an exposure surface. It is a planar surface with a few small pits but overall there is no evidence of the kind of disruptive features you see underneath younger disconformities.
This cycle is part of a cyclic sequence. I could never get a handle on the individual cycle frequency but using regional stratigraphic markers and conodont biostratigraphy a rough estimate is that surface was exposed for tens of thousands of years during Richmondian sea level falls. There is plenty of microscopic evidence of exposure in the form of preserved vadose diagenetic fabrics, but in the field it looks just like a bedding plane. In the late Ordovician there was a land plant cover but it was mostly of the bryophyte grade i.e. mosses and liverworts. These plants don't have disruptive root systems and don't release the massive quantities of organic acids for penetrative weathering profiles to develop.
There are other controls in carbonate systems that can form karstic surfaces in the absence of land plants. One is the facies setting. Supratidal and sabkha facies with dolomite and evaporite minerals dissolve quickly in carbonate under saturated groundwater and these facies often develop the kind of disruptive weathering profiles you associated with a land plant cover.
And the other control is time. Very long lived exposure of limestone, surfaces that are exposed to meteoric condition for tens of millions of years will eventually succumb and form distinctive karst. The image below is of the Knox unconformity between lower Ordovician passive margin platform carbonates and a mid Ordovician foreland basin sequence.
The Knox surface developed during a major sea-level fall that lasted at least 10 million years. A mature karst terrain developed across facies tracts. Sinkhole and caverns fills and intraformational breccias can be seen to depths of 250 m beneath the unconformity.
There have been a couple of recent studies that make connections between evolution and geological processes. One dealt with an increase in diversity in mineral species after the evolution of photosynthesis. The other pointed out a connection between sea water chemistry, evolution of animals and skeletal mineralogy.
Geology may influence evolution. The paper points out that the early radiation of land plants likely took place in alkaline groundwaters. That may explain the affinity for alkali shown by many land plant groups. Subsequently as plant life took hold over terra firma, evolution influenced geology through the transition to acidic groundwater, detrital and diagenetic sediment composition, element mobility and soil composition and characteristics of disconformities.
See: Geological Processes and Evolution
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