Identifying Igneous Rocks

What are rocks?

Common minerals.

Sedimentary and metamorphic rocks.

Igneous Rocks

The relative amounts of just three main minerals; quartz, plagioclase feldspar, and potassium feldspar are all you need to know to start identifying igneous rocks. In addition to these three light-colored, felsic minerals, the abundance of dark, mafic minerals can also help you distinguish one type of igneous rock from another.

Once you know you have an igneous rock, look at the texture to decide if it is intrusive (big crystals) or extrusive (fine texture). Then use this chart to make your first guess based on how dark (mafic) or light (felsic) your rock appears.

To be sure you've named your rock correctly you need to compare the amounts of plagioclase feldspar, potassium feldspar, and quartz and plot it on the triangular graph.

Try this: suppose your rock is coarse-grained, so you know it's intrusive. It has 40% quartz, 30% potassium feldspar, and 30% plagioclase feldspar, it's called granite.

--Taken from USGS Geology in the Parks.

Herbarium Curation

Sagehen uses volunteers to manage its collections, including our herbarium. Here are some useful documents to help you understand the principles and strategy.

IMPORTANT! Be scrupulous about your field and lab notes. Keep a lab journal and field notebook. Document everything you do! Your effort is wasted--or even destructive--if you (and others) cannot later figure out what you did.

Organization and Management

• Sagehen Herbarium Curation and Workflow, 2020
• Sagehen Herbarium Guidelines 
• Digital collection. Sagehen's herbarium vouchers have been digitized and are available online at CCH2.org. 
• Herbarium Collection Needs & Notes, 2020

https://www.capturingcaliforniasflowers.org/workflow--protocols.html

* * * 

Thanks to all our Sagehen Herbarium volunteers to date!

• Erica Krimmel: program development; collections organization; digitizing; herbarium expansion; volunteer management.
• Alex Gallandt: accessioning; mounting; collecting; updating taxonomy; reorganizing collection schema.
• Angele Carroll: plant mounting; voucher filing
• Hannah Johansson: accessioning assistance
• All the California Naturalists and Weed Warriors who have helped at plant mounting days! 

 

Botany tools

Here are some useful tools to help you with your iNaturalist botanical observations in the Sierra Nevada.

Tools:

• See this link for information about how to choose a hand lens, and how to take better plant pictures.
• Plant collecting and documenting field notebook: with fields already printed, so you don't have to remember them all!
• This is a fantastic visual guide to cryptic and poetic botanical vocabulary.

Cheat sheets:

See this link for more information:
http://www.northernontarioflora.ca/inflorescence_types.cfm 

Field workshops:

Field courses from the California Native Plant Society, or the Jepson Herbarium will really jumpstart your identification skills. You'll also meet other botanists and enthusiasts that you can spend time with in the field. That's the trick to really learning botany.

There are workshops at all levels, and many are incredibly technical. If you are a beginner, look for "Introduction to..." courses.

Plant keys:

A dichotomous key helps you identify plants by leading you through a branching series of "This or that?" questions until you--hopefully--reach a species or finer ID. Be advised that keying can be a bit of an art and it helps to do it with a friend or three. It also helps tons to get to Family or even Genus before consulting the key, and you will definitely need a botanical dictionary to tease out the difference between arcane terms like, say, "puberulent" and "pubescent".

The Jepson Manual (TMJ2) is the 800-lb gorilla, with complete listings for California plants and an active and dynamic community constantly working to update it. Other states tear their eyes out with envy.

Unfortunately, the book itself actually weighs about 800-lbs. It's a pain in the lumbar to tote it around the field.

Fortunately, an e-Flora with the same data is on-line (for the office), and there's an e-Book version now for your iPad or other device for use in the field (by some accounts the Kindle version is more user-friendly).

Another option is the Weeden key. Less complete and up-to-date than TJM2, but very portable, it is still incredibly popular despite being out of print for a couple of decades. Keep a weather-eye out when trolling used book sales, and grab as many as you can if they're cheap--you won't have any trouble finding homes for them.

Plant keys can be tricky, and it seems to work best to use them as a group effort to smooth out the interpretation factor. You'll definitely need a good loupe to see the characters described...and sometimes a dissecting scope for some families (like, the Sunflower Family). You can use a key to get better at identifying Families by sight, which you will find really boosts your game and makes botanizing more fun!

Online Courses:

• Charles Sturt University Virtual Herbarium. Learning botany starts with understanding flowers. Once you grasp floral formulas, you can identify Families, and then you are off and running! This site has an incredible interactive tutorial and testing tools for leaves, gynoecium and floral formulae that teach you to see and understand the unique structural patterns of leaves, sepals, petals, androecium and gynoecium that make up plants and flowers, and which arrange them taxonomically.
• Lab for UC Davis Plant Sciences 102.
• "Connecting Students to Citizen Science and Curated Collections" is a fantastic introduction to plant collecting, pressing, identifying, and documenting using iNaturalist.
• Webinar on the above collections program. If you are interested in the didactics of this program, and why it includes the content it does, watch this.

Field Guides

Field guides are easy enough to find, but here are some harder-to-find tools you can use to develop your identification skills. I'll update this page from time to time if I find particularly good resources.

• Sagehen Basin Custom Field Guides: we have created downloadable iNaturalist field guides to Sagehen botany (and other biota) for your smart device that will help you identify the most likely candidates in the Sagehen basin and adjacent areas. 
• Guide to Western Bumblebees. You would think that bumblebees would be easy to identify, but it turns out to be non-trivial. Fortunately, there's now a real guide to western bumblebees.
• Butterfly Families. There are really only 6 Families of butterflies, and learning them will jumpstart your IDs, giving you the skill to immediately narrow down the candidates.
• Feathers: identifying feathers can be a challenge, but here are a couple of really good resources:
• Bird Feathers: A Guide to North American Species, Scott and McFarland
• The Feather Atlas: Flight Feathers of North American Birds

BioBlitz model

 Kaitlin Backlund organized Sagehen's first BioBlitz in 2015, and it was a great success, due to excellent planning. See more photos.

Kait has generously shared her management tools with us for the next event.

Volunteer Shift Schedule | Sagehen BioBlitz Guide

From Kaitlin:

Here is some info for a BioBlitz. Its a lot of work, but also a ton of fun. I recommend reading through items here. http://www.inaturalist.org/pages/bioblitz+guide

I relied heavily on the Nerds for Nature Guide and have attached their 10 Step Guide with modifications made for the 2015 Sagehen Blitz in green print. Also attached is the Volunteer Shift Schedule. The Sagehen Blitz was a highly managed event because it was held at a Field Station, but as you will see by looking at other Blitzs, there are a variety of formats. (I happened to use Nat Geo's Blitz at Hawaii's Volcano National Park as a template.) It is also worth noting that the BioBlitz Guide doesn't discuss liability etc.. which is something you should discuss with whoever you partner with to do a Blitz.Most groups or agencies that work with volunteers in the field have procedures in place for you to follow.

I hope this is helpful!

Sagehen Mammal Collection digitization project

A specimen label needing to be transcribed.

Sagehen is busy digitizing and curating our teaching collections to share with large data portals, creating new research and citizen science opportunities. With the advent of new technologies, like various isotopic and genetic sampling techniques, old collections are yielding important new information that informs research into changing environmental conditions. Here's one spectacular an unexpected example from Sagehen's visiting artists program. And another from our research program, where DNA from fur samples was compared with historic museum specimens to determine relatedness, and isotopes confirmed where the animal had been drinking its water.

At present, we need help digitizing the labels from our mammal collection. You can help out from home using the instructions found here.

UPDATE, 8-4-19: we have largely completed the first phase of this project. All animal skin records are now available to researchers and the public through CSVColl.org, a Symbiota portal. Select "Sagehen Creek Field Station (UC-Berkeley) - Mammals (SCFS-Mammals)". Complete transcribed label data is available here.

This project was completed thanks to the efforts of Erica Krimmel, Sagehen Collections Manager, and our amazing volunteers:

• Terry and Emily Gollub, Sagehen California Naturalist (specimen photography)
• Alexander and Robert Gallandt, Volunteers (label transcription)
• Kathy Mullen, Sagehen California Naturalist (label transcription)

We still need to accession our collections of bones, scat, hair and fish scale slides, so keep an eye out for announcements. If you would like to help right now, we have a Zooniverse project that needs your help identifying animals in camera trap photos.

iNaturalist Animal Track Project

Here's a great description of an iNaturalist project that you might like to participate in, or on which to model your own project.